Expansion counterboring bit for wood



Patented May 9, 1922.

Z7 *3 I INVENTOR. WTPI/Z UNITED STATES PATENT OFFICE.

WILLIE F. WALL, OF SAN FRANCISCO, CALIFORNIA.

EXPANSION COUNTERBORING BIT FOR WOOD.

Specification of Letters Patent.

Patented May 9, 1922.

Application filed October 29, 1920. Serial No. 420,456.'

.Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Expansion Counter-boring Bits for Wood; and .I do hereby declare the following to be a full, clear, and exact description of the in vention, such as will enable others skilled in the art to which it appertains to make and use the same. p

This invention relates to improvements in wood boring bits, and its primary object is the provision of a combined boring and counter-boring bit of novel, simple and ellicient construction.

A further object of the invention is the provision of a combined boring and counterboring bit having a head provided with a tapered portion adapted to engage the edge ofthe hole being counter-bored'and thereby form a centering support for the bit during the counter-boring operation.

A further object of the inventionis the provision of a combined boring and counterboring bit having a cutter blade adjustable axially on the bit head to permit the centerin support to engage the edges of holes of difi'erent diameters.

A still further object of the invention is the provision of a combined boring and counter-boring bit wherein the cutter blade is also adjustable laterally with respect to the bit head, whereby to permit the bit to be used for boring counter-bores of different diameters.

A still further object of the invention is to provide a combinedexpansion and counter boring bit which shall be simple, durable and efficient, which may be readily and quickly adjusted for boring holes of various diameters and for counter boring the holes, and which may be manufactured and sold at a comparatively low cost.

With the above and other objects in view, the invention consists in the construction, combination and arrangement of parts here inafter fully described and claimed, and illustrated in the accompanying drawings, wherein:

Figure 1 is a view in front elevation of a combined expansion and counter boring bit constructed in accordance with my invention, the cutter blade being shown in position to adapt the bit for boring holes.

Figure 2 is a view similar to Figure 1, they cutter-blade being shown in position to adapt the bit for counter-boring a hole.

Figure 3 1s a view 111 side elevation of the bit Figure t is a detail perspective view of the clamp employed to'secure the cutter blade in various positions upon the bit head, and

Figure 5 is a detail view in rear elevation oi' the cutter blade.

Referring to the drawings by reference numerals, 1O designates the shank and 11 the head of my improved combined expansion and counter boring bit. The head 11 embodies an upper portion 12 of semi-cylindrical formation and a lower portion 13 of inverted semi-conical formation. The flat sides oi the head portions 12 and 13 are arranged in the same plane and in the plane of the vertical. axis of the shank 10. A lead screw let and a cutting lip or flange 15 of well known constructions are carried by the lower end of the head portion 18. The flat side of the head 11 is provided with laterally and longitudinally disposed serrations 16 which are adapted to be engaged by similar serrations 17 provided on the rear side of a cutter blade 18. A clamp 19 is employed to secure the cutter blade 18 in position upon the head 11, and it is provided with ahead 20 having serrations 21 corresponding to the serrations 16 of the bit head 11. The clamp 19 is secured in position by a screw 22 which passes through the clamp and enters one oi a plurality of screw threaded openings 23 in the head 11.

As the serrations 16, 17 and 21 extend in two directions, the cutter blade 18 will be held against any lateral or axial movement with relation to the head 11 during the use of the bit. The cutter blade 18 has a cutting edge 24 and a spur 25, and it is adapted to be clamped in the position shown in Figure l of the drawing when it is desired to use the bit for boring a hole. "When in this position, the cutter blade 18 may be adjusted laterally with respect to the head 11 to adapt the hit for boring holes oi various diameters. On its front side, the cutter blade is provided near its lower edge with a scale 26 which is designed for comparison with one of the inclined lateral edges of the fiat side of the head 11 in arranging the cutter blade to produce a hole oi. the desired diameter.

When it is desired to counterbore a hole, the cutter blade 18 is moved upwardly upon the head 11 into a position such as that shown in Figure 2 of the drawings. To secure the cutter blade in this position the clamp 19 is inverted. As shown in Figure 2- of the drawing the head portion 13 engages the edge of the hole and forms a centering support forthe bit during the counter-boring operation. The degree of the axial adjustment of the cutter blade 18 depends upon the diameter of the hole to be counter-bored. Knowing the diameter of the hole, the degree of the axial adjustment of the cutting blade may be readily determined by reading the scale 27 upon the head portion 13. To enable the cutter blade to be readily and quickly adjusted for boring counter-bores of various diameters, the cutter blade 18 is provided on its front face with a scale 28 which is designed for comparison with one of the inclined side edges of the fiat side of the head 11.

Itshould be apparent from the foregoing -description, taken in connection with the accompanying drawing, that I have provided a bit by means of which holes of various diameters may be bored and by means of which the holes may be provided with counter-bores having diameters commensurate with the diameters of the holes. It should also be apparent that the cutter blade may be readily and quickly adjusted to adapt the bit for boringholes or counterbores of various diameters that the cutter blade cannot have any' movement with respect to the bit head during the boring or counter-boring operation, and that the semi conical portion of the bit head forms a centering support for the bit during the counter-boring operation.

What is claimed is 1. 'A combined expansion and counter-boring bit comprising a head having a lower semi-conical portion and an upper semi-cylindrical portion and provided at the lower end of said semi-conical portion with a lead screwand a cutting lip or flange, the flat sides of the head portions being located at the same plane and in the plane of the axis of the bit, a cutter blade, andmeans for securing the cutter blade to the fiat side of the head for radial and axial adjustment with respect to the head.

A combined expansion and counter-boring bit comprising a head provided with a tapered lower end and with a lead screw and cutting lip or flange, a cutter blade, and means for securing the cutter blade to the head for radial and axial adjustment with respect thereto.

3. A combined expansion and counter-boring bit comprising a head provided with a tapered lower end and with a lead screw and a cutting lip or flange and having a flat face provided with longitudinally and transversally disposed serrations, a cutter blade provided with similar serrations, and a cutter blade clamp provided with similar serrations, the clamp securing the cutter blades of the head for radial and axial adjustment with respect thereto.

at. A combined expansion and counter-boring bit comprising a head provided with a tapered lower end and with a flat face and with a plurality of relatively spaced threaded openings extending transversely therethrough, said fiat face having serrations, a lead screw and cutting lip or flange carried by the head, a cutter blade provided with serrations, a cutter clamp provided with serrations, and screws passing through the clamp and entering one of said o iienings, the clamp securing the cutter blade in position for radial and axial adjustment with respect to the head.

5. A combined expansion and counterboring bit comprising a head having a flat serrated face in alinement with the axis of the bit and having an upper semi-cylnnlrical portion and a lower semi-conical portion located on the same side 01" said face, a lead screw and a cutting lip or flange carried by the lower end of said conical portion, a cutter blade provided with serrations, and a cutting blade clamp provided with serrations, and means adapted to secure said clamp in different positions to the flat side of the head.

6. A combined expansion and counterlooring bit having a tapered lower end adapted to enter the opening being counter-bored and form a support for the lower end of the bit, a cutter blade. and means for securing the cutter blade to said lower end for radial and axial adjustment with respect thereto.

7. A bit having a head provided with a tapered portion adapted to form a centering support during the c n1nter-boring operation, a cutter blade, and means securiiny; the cutter blade to the head for axial adj ustinent with respect thereto.

In testimony whereof I aiiix my signature WILLIE F. \VAliL. 

